The Lyon transport network is the second largest in France, with over 140 metro, bus, tram, funicular and trolleybus lines supporting 1.8 million trips each day. As part of its strategy to reduce car use, local transport authority Sytral Mobilités opened the 6.7km-long T6 Tramline in 2019 to connect the Debourg area of the city and hospitals to the east.
Following the successful opening of the T6 line, Sytral Mobilités decided to extend it to La Doua university campus. The new extension will be 5.4km long, include 11 new stations and carry 55,000 passengers each day, enabling people to travel on a ring road tramline around the entire centre of Lyon.
Egis was appointed to project manage the line extension and, with main contractor TSO, began work at the end of 2022.
To ensure the 1,230 aluminothermic welds needed are completed efficiently, ergonomically and safely, the TSO team decided to use Pandrol’s i+weld technology The tram rails are manufactured from grooved steel – standard grade R200 and R260 for straight lines, and hard grade R290 and R320 for turns. i+weld uses semi-automated processes to reduce the physical strain on welders, ensure weld quality and conformity, and speed up completion. TSO welders are using two tools from the i+weld range:
• AutoSeal® moulds – which streamline the welding process by removing the need for luting (sealing moulds to rail ends with paste or sand to avoid metal leaks). Instead, a built-in strip expands during the pre-heating phase to create a tight seal between the mould and the rail.
• the High Flow Preheater (HFP) 36V – which offers a fully automated, battery powered solution for preheating, including ignition, timing and stop.
Both AutoSeal® and the HFP 36V save time and maximise weld efficiency and performance, which are important factors on a project of this scale. Saving five to ten minutes on mould sealing and an additional six minutes on preheating makes a noticeable difference on projects like this, where productivity is a key priority.
Colleague wellbeing is a particular priority for TSO, and played an important part in the decision to use the i+weld range. The HFP 36V only uses propane, so is significantly safer to use than traditional oxy-propane equipment. And as Daniel Poulet, a welder on the project explains: “Using i+weld has resulted in a much more comfortable, less stressful process for welders. We no longer have to stay on our knees for 10 minutes, scraping, adding paste, bending over to manage the burner. The seal is done automatically at preheating, saving time and providing ease of use". Sustainability was also a factor in the choice of i+weld : "not using paste for sealing means less plastic waste and using the HFP 36V reduces gas consumption."
Nicolas Demond, Head of Engineering ATW/EQC from Pandrol, explains: “Using i+weld makes rail welding a more comfortable, quicker and more convenient process. There is no need to handle oxygen, the seal is done automatically at preheating, saving time and making the whole process more efficient. Sustainability was also a factor in the choice of i+weld – not using paste for sealing means less plastic waste.”
In addition to its aluminothermic welding system, Pandrol’s NABLA Evolution rail fastening system was installed across a total of over 15,000 sleepers.
Pandrol’s NABLA Evolution Rail Fastening system, which is designed for use on state-of-the-art tram and light rail systems, is also widely implemented on other sections of Lyon’s tram network.
“In the first welding section completed, I did not find a fault. i+weld is proving higher quality, more sustainable and more convenient to use – I have only seen positive points.”
Mbarki Hafid, Works Supervisor, TSO
To date (November 2024), TSO welding team has completed 1,230 welds using AutoSeal® moulds and the High Flow Preheater (HFP) 36V. The use of innovative, cutting-edge technology and automation is making a major contribution to the efficient extension of the T6 line.
Once complete, the new line will be instrumental in continuing the shift from private car to public transport in Lyon, resulting in a more peaceful and less polluted city.
